Process of smelting and purifying iron.



Patented Sept. 15, 19M.

G. R. GEHRANDT. PROCESS 0F SMELTING AND PURIFYING .IRONi n APPLICATION'FILED .TUNE 14, 1913,

`cinder-notch 8, cinder-n`otch 9 being plugged in due season. The molteniron thus rises over the mouths of the twyers 7, and, hence, theair-blast from pipe 5 will pierce the metal and oxidize the impuritiesof the molten iron. By regulating the quantity, temperature, andpressur'e of the blast it is possible to dctcrn'iine, Within reasonablelimits, the chemical constituency of the pig iron. The blast from theupper twyers 6 will not pierce the metal, but will pass through the mixinv the bosh 2 and stack l in the usual manner.

From one point of view, the twyers (i are only emergency twyers, forordinarily the loblique twyerswill deliver enough air for the entireprocess, including both the smelting and the dccarburizing,notwithstanding, the fact that much of the oxygen delivered thereby isconsumed and utilized when pass ing throughy 'the iron; but it is betterand saier to provide the two sets of twyers 'than to rely upon one setalone, for at times when .the llow of air through' tivyers 7 is checked,

possibly not enough air would be deliveredto furnish the oxygen requiredfor the smelting process. ,With two sets of tivyers, one can be used forthe smelting and the other for the oxidizing, and each set controlled atwill, without any fearA that the smelt'ing will be impaired merelybecause only a short air-supply is required for the oxidization. A

lt is to be observed that this invention is not a direct process ofproducing steel itself 'from iron ore, for While the final product ofthis invention is an iron which is freed, in Whole or in part, fromcarbon, silicon, and other metallic and non-metallic inipurities, themolten metal escaping from the iron notch l0 still. requires furthertreatment to convert it into steel. The pig iron produced by thisinvention is, however, a refined or purified pig, and is a product whichcan be used for countless purposes for which ordinary commercial lpig isunsuitable, unless it be further treated by some process of purificationor refining.

ln the practice of the invention, the inolten iron in the hearth 3 isallowed to accumulate until it stands at a. higher level v thanthemouths of the tivyers 7. There will,

of course, be a layer of slag on top of the mass of molten iron, whichslag can be drawn oil from time to time through the cinder-notch 8. Theair-blast from the twyers 7 `will enter the body of molten iron .nearits outer and 'upper edge, .and the stream oit air Will enter and piercethe Inolten iron and slag. following oblique paths, the angle of whichdepends upon the 'angle of inclination of the twyers 7. 'lheblast fromthe twyers 6 will enter the furnace, foilowing paths which areapproximately hori zontal at vthe mouths of the twyers It -varicusstrc-ams from the obliquely-disposed twycrs a will tend to pierce thebody of moiten iron 'near the upper level andyto pierce theslag, passingthrough both metal and slag?r at an oblique angle, and streams fromtwyers 7- will center at approximately the median line oil they stach.vSome of the oxygen oi the air which enters through the oblique twye'rs7 will be exhausted in passing through. the molten iron and slag, but anadditional volume of oxygen will be supplied by the air from twyers..Because of the forming of this air umbrella, every particle oi' smeltedore dropping from the stack or bush into thehearth mustpass through theheated air before reaching the hearth, and every such particle ofsmelted ore is, accordingly, vpartly purilied before it even reaches thehearth.:

ln a blast furnace of ordinary size, 'it is customary to collectapproximately 150 tons of molten metal in the hearth, and should theairblast enter this body of metal near the bottom, it is certain that theagitation thus caused would eventually rupture even the strongestfurnace, Whereas, 1n this invention ily-.causing the stream of air toenter near the top of the body of molten metal, the agitation within thehearth is kept Well Within the limits oi safety. Moreover, were `thejets oiE air to enter near the bottom of blast to pierce the metal, andit would be necessary to provide either more air-compressors orcompressors oi greater .power in order to overcome the resistance andWeight of the entirebody of metal than are required where the streams ofair enter near the top level of the `molten metal. By' arranging thetyvyers 7 near the top level of the molteny metal, the air-blast whichpierces the metal is not required vto beunder an abnormal or anexcessive pressure; whereas, if the twyers 7 were to enter the hearth ator nearits bottom, the pressure required to enable the air blast topierce the metal would be excessive. lccause of the fact that theair-blast `from the t'Wyers 7 pass obliquely through the. metal, itfollows that the a ,agitation of the mass of molten .metal is confinedtoacircular or annular space, andthe metal or slag We eed en@ me es havepassed of its impuifitiee so freed. The heevie' 'a comme, sink to 'theeo; it is epeeed 'by impure metu which Y tofiie top, and it f ioice thestx'eem e metal within he y zhe eiitiie mese bled oie in Le and incausieieai iioii und' et ego angie ehm-bie 'a being passed through theiron siefiuioeneoueijee he euppiy of iron in the hemh if, ieplenisiiedby i'eshiy smeited iron from ebow-5.

The herein iibed 'process of goeinem@ purified iron which oonsist ineme-,i ng the ore, eoiieetiiig elle moteiimess tous oveined in ke,z-ece'pmcie beneath the rse, and in eene-ing an air-Meet to enei andpiei'ee said. molten mess et e point adjacent the top ieveio sai massand 'to tiave oblifyieiy o the ieve of seid massi, said eirbies being@esseri through the molten mass beiseite iie seme is wie-iifiown fromthe reeeli-zfeie. y

iiie .iieyeiio fieseibed pi'ocess of proemeing e pufied iion whichconsiss in emeiiegg the ore, collecting the reduced moitexi .iron inHee. smeii'ng apparatus., and eo eetei the moiten ne 3 iie iippef ievei.the booiyichere'- ein, omi 'in 'uiftioei Causing; seid albiast to meiiioogh seid iron W ile the seme stili iei'neiie in the i'ecepteeie'Witiizi which it has been collected. i

49., The heee-iii deseribed psooess of producing e purified; ironconsisting in smeiting he ore, collecting the reduced ore in the heezzhof ehe sgneting furnace, and in oeu'sing an air-bie to enei eind piercethe .iron et a point adjacent the uppei- 1evei`0f the' iron, seid:lili-biagi; being passed through the iron in ehe hearth simultaneouslyes the supply ef iron in the oearh is replenished by 'iesixiy emetedironiz'oui above.

5. 'She oe'ein described process 01"' pm dosing puriied oxi whicheo-usiss in smeiug the ore, ooieeting the reduced omiten iron in 'thesmeiting apparatus, in causing amv eil-blee to enter the moiten ironmeer the upper ieve of the body there- *he eyeif l oblique the level ofzie smeitec'iviron, seid omero@ booe o ,s

'oi in further causing seid aix1 blast pass through said molten ii'onwhilelthe seme etiii remains in the 1'.'eeepmele Within which it 'onsbeen colleen-d, and in causing another eibast to enter intermediate the.upper level of the reduced molten iron and the body o the ore.

in testimony 'whereof hereunto aix my signature in the presence of twoWitnesses. GUSTAi/TE R. GEHRANDT. 'Vivisneeses Row. Humm.) f

i Ruime? R. GOLDSMHH.

